1. Field of the Invention
The present invention relates to new crystalline zeolite SSZ-54, a method for preparing SSZ-54 using a templating agent comprising N-isopropyl ethylenediamine, or a mixture of 1-N-isopropyl diethylenetriamine and isobutylamine, and processes employing SSZ-54 in a catalyst.
2. State of the Art
Because of their unique sieving characteristics, as well as their catalytic properties, crystalline molecular sieves and zeolites are especially useful in applications such as hydrocarbon conversion, gas drying and separation. Although many different crystalline molecular sieves have been disclosed, there is a continuing need for new zeolites with desirable properties for gas separation and drying, hydrocarbon and chemical conversions, and other applications. New zeolites may contain novel internal pore architectures, providing enhanced selectivities in these processes.
Crystalline aluminosilicates are usually prepared from aqueous reaction mixtures containing alkali or alkaline earth metal oxides, silica, and alumina. Crystalline borosilicates are usually prepared under similar reaction conditions except that boron is used in place of aluminum. By varying the synthesis conditions and the composition of the reaction mixture, different zeolites can often be formed.
The present invention is directed to a family of crystalline molecular sieves with unique properties, referred to herein as xe2x80x9czeolite SSZ-54xe2x80x9d or simply xe2x80x9cSSZ-54xe2x80x9d. Preferably, SSZ-54 is obtained in its silicate, aluminosilicate, titanosilicate, vanadosilicate or borosilicate form. The term xe2x80x9csilicatexe2x80x9d refers to a zeolite having a high mole ratio of silicon oxide relative to aluminum oxide, preferably a mole ratio greater than 100, including zeolites composed entirely of silicon oxide. As used herein, the term xe2x80x9caluminosilicatexe2x80x9d refers to a zeolite containing both alumina and silica and the term xe2x80x9cborosilicatexe2x80x9d refers to a zeolite containing oxides of both boron and silicon.
In accordance with this invention, there is provided a zeolite having a mole ratio greater than about 20 of an oxide of a first tetravalent element to an oxide of a second tetravalent element different from said first tetravalent element, trivalent element, pentavalent element or mixture thereof and having, after calcination, the X-ray diffraction pattern of FIG. 1.
Further, in accordance with this invention, there is provided a zeolite having a mole ratio greater than about 20 of an oxide selected from silicon oxide, germanium oxide and mixtures thereof to an oxide selected from aluminum oxide, gallium oxide, iron oxide, boron oxide, titanium oxide, indium oxide, vanadium oxide and mixtures thereof and having, after calcination, the X-ray diffraction pattern of FIG. 1.
The present invention further provides such a zeolite having a composition, as synthesized and in the anhydrous state, in terms of mole ratios as follows:
wherein Y is silicon, germanium or a mixture thereof; W is aluminum, gallium, iron, boron, titanium, indium, vanadium or mixtures thereof; c is 1 or 2; d is 2 when c is 1 (i.e., W is tetravalent) or d is 3 or 5 when c is 2 (i.e., d is 3 when W is trivalent or 5 when W is pentavalent); M is an alkali metal cation, alkaline earth metal cation or mixtures thereof (M is preferably potassium); n is the valence of M (i.e., 1 or 2); and Q is N-isopropyl ethylenediamine, or a mixture of 1-N-isopropyl diethylenetriamine and isobutylamine.
In accordance with this invention, there is also provided a zeolite prepared by thermally treating a zeolite having a mole ratio of an oxide selected from silicon oxide, germanium oxide and mixtures thereof to an oxide selected from aluminum oxide, gallium oxide, iron oxide, boron oxide, titanium oxide, indium oxide, vanadium oxide and mixtures thereof greater than about 20 at a temperature of from about 200xc2x0 C. to about 800xc2x0 C., the thus-prepared zeolite having the X-ray diffraction pattern of FIG. 1. The present invention also includes this thus-prepared zeolite which is predominantly in the hydrogen form, which hydrogen form is prepared by ion exchanging with an acid or with a solution of an ammonium salt followed by a second calcination.
Also provided in accordance with the present invention is a method of preparing a crystalline material comprising an oxide of a first tetravalent element and an oxide of a second tetravalent element which is different from said first tetravalent element, trivalent element, pentavalent element or mixture thereof, said method comprising contacting under crystallization conditions sources of said oxides and a templating agent comprising N-isopropyl ethylenediamine, or a mixture of 1-N-isopropyl diethylenetriamine and isobutylamine.